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Severe Ghosting problem with J-PAC
BobA:
--- Quote from: AndyWarne on November 12, 2010, 03:59:52 am ---
The workaround for this is to connect 100nF disk ceramic capacitors across each of the offending switches.
--- End quote ---
Thanks Andy - Good to know, that is much cheaper then ferrite cores.
BuriedEgg:
Well, I'm at work now. I've had the laptop test running for an hour straight now with no auto-typing at all, whatsoever. This means its the RFI/EMI in my house for sure.
I'm going to track down some of those 100nf capacitors mentioned here. I will post results.
I want everybody reading this thread to know that this is a problem with interference in my house, not a problem with the J-PAC itself. It says a lot about Andy's excellent support for his products that he is -still- actively troubleshooting this with me even though it clearly isn't technically his product's problem anymore.
I wish the company that built my home felt this way about customer support! ...or the company that built my car, or my HDTV, or my refridgerator, or my... oh you get the point. Way to go supporting the Home Arcade Electronics Community, Andy!
cotmm68030: I will definitely try that radio antenna experiment with my sound card and report back! That sounds really cool. I will record with Audacity and attach results.
AndyWarne:
--- Quote from: pinballjim on November 12, 2010, 11:50:38 am --- I used to have one that would occasionally go berserk and crash everything, and isolated the problem down to the JPAC. (the line of BS I was fed at the time was I had clearly plugged it into my keyed connector backwards and fried something with the invisible power supply I didn't know was in my cabinet)
--- End quote ---
Well that would not have come from me. I have never once stated that any problem with a J-PAC has definitely been caused by plugging it in backwards. I might have suggested it as a possible cause amongst many others, in the interests of trying to assist with troubleshooting, but that would not have prevented us from repairing/replacing it which I hope we did in your case. I do not give my customers BS ever.
BuriedEgg:
Okay, Preliminary Results Time and things look good!
(Photo attached at bottom in case anyone else runs into this problem in the future)
I found the Ceramic Disc Capacitors today but the store only had 4 of them. I bought them but decided to test with the Choke Cores first instead:
Attached 2 big Choke Cores to the main wires of the JAMMA harness as close as possible to edge connector. Was able to make only one full turn around each core.
Choke Core: http://www.radioshack.com/product/index.jsp?productId=2103979#
Then attached one smaller snap-on choke to the Kick Harness wires (the screw-connector wires on J-PAC) and one more to the extra disconnected wires (speaker/power/video) left over hanging loose from the main JAMMA harness:
Smaller Snap-On Choke: http://www.radioshack.com/product/index.jsp?productId=2103222
I ran the cabinet for about 3 hours last night and 2 more hours this morning with not one single phantom key-press or F2 reset.
I want to say this is resolved but I'll wait till Monday. It usually takes about 5 minutes to get the thing to start auto-typing keys but I've gone long stretches without it happening in the past.
Will update everyone on Monday.
The following pic is a side view of the 4 chokes on my wiring. The fourth choke, attached to the kick harness wires, is out of view right below the main edge connector.
I don't want to hear anything from anybody about the spaghetti mess in there! I keep a neat cabinet! Its messy because I've been tearing my nice neat harness up for the last week. Thanks guys!
BuriedEgg:
Here is another pic revealing the lower portion where the screw connector wires are running thru the smaller choke. I was able to get an extra turn thru this choke.
(For anyone who may be experiencing this problem and wants to know how I applied the fix)